Compilare: user.cpp: In function ‘int main()’: user.cpp:58:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("rj.in" , "r" , stdin); ^ user.cpp:59:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("rj.out" , "w" , stdout); ^ user.cpp:60:32: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d %d\n" , &n ,&m ); ^ user.cpp:73:28: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets( sir + 1 ); ^ /tmp/ccOLuSVa.o: In function `main': user.cpp:(.text.startup+0x128): warning: the `gets' function is dangerous and should not be used.